Air compressing internal combustion engine with direct injection

ABSTRACT

An air compressing direct injection internal combustion engine in which either the reciprocatory piston or the pertaining cylinder head has a ball-shaped combustion chamber therein which is provided with a neck that is constricted with regard to the diameter of said combustion chamber and which is adapted so to receive the combustion air as to circulate the same in said combustion chamber, the ratio of the diameter of the said combustion chamber to the diameter of said neck being less than or at the maximum equalling 1.15 while the fuel injection nozzle is so directed toward the inside of said combustion chamber that the point of impact of the fuel jet upon the inside surface of said combustion chamber is located in that quarter of the combustion chamber which is remote from and opposite to said constriction.

United States Patent 1m nu 3314.066 Liihr l 5l June 4. 1974 1 All! COMPRESSING INTERNAL 3 2.23! :n vn: zit-wt; 12:12 It .88.." .190 .xpc co. IJIJR gggggg mm 3.124.111 mww (ilkflkl mun R m Nmmm" FOREIGN PATENTS on APPLlCATlONS y 211N530 tlltum Germany /.m I) [73] Assignee: Muehlnenlabrih m e- Primry rnn|inrrl.t|urence M. Gtmdridgc cAgtictlgeae'lhehait. Nurnherg. Armmry. Agent. or Firm-Walter Becker rmany |22| Filed: July 2a. m: ml ABSTRACT An air compressing direct injcctiim internal combuslzl I tion engine in which either the reciprocatory piston or the pertaining cylinder head hau a hull-ashamed com- [MII Ford Applkntbq my I). hulliflt'l chamber therein which hi pmvidcd with at 1 J W7" 2" m neck that is constricted with regard to the diameter ot said combustion chamber and which is adapted in in 51 u c; u I receive the combustion air as to circulate the name in 5 CL laid combustion chamber. the ratio of the diameter or 5y r s zym 30 C. 32 32 the mid combustion chamber to the diameter of mid 23,32 59 neck being lea than or at the maximum equalling l.l$ while the fuel injection nozzle is m directed toward MI 5m cm the inside of said combustion chamber that the point 0 impact of the fuel jet upon the imidc surface of said UMTED STATES PATENTS combustion chamber is located in that quarter of the xxx combution chamber which in remote from and opporIvzlIsii uni." nwm'IfII III x1313: a 235mm tum-u Battier Ill/J2 It I Claim. 3 Drunk g Figures 1 AIR CO'iIPRESSING INTERNAL (Tflllll'STlON ENGINE WITH DIRECT INJECTION the present invention relates to an air compressing internal combustion engine with direct injection which has a ball-shaped combustion chamber pros ided in the piston or cylinder hcad which combustion chamber is provided with a neck constricted with regard iii the di- .imctcr of the combustion chamber. More specifically. the invention concerns an internal combustion engine of the just mentioned type in which the major portion of the liquid fuel is in the form of a film injected onto the wall of the combustion chamber while the air supplied to the combustion chamber rotates about the long'itudinal axis of the combustion chamber.

It is a well known fact that in particular with internal combustion engines of the above described type during the idling stroke and also in the lower and medium partial load range the formation of blue smoite occurs which has a polluting effect and irritates the eyes and .iffects the breathing. The reason for the formation of blue smoke is too low a temperature of the wall of the ombustion chamber so that a satisfactory combustion cannot take place. A poor combustion. on the other hand. aids in the formation of aldehydes. acroleine. -pecif'ic hydrocarbons, among others. in the exhaust gase in oyereome these drawbacks it has been suggested to increase the compression ratio of the engine or to employ a twist inhibitor for the rotating air in the coml' usllt rt chamber. Furthermore. the location of the fuel et was within these ranges of operation changed to such an extent that the proportion of the fuel directly intermixed with the combustion air became correy ondingly greater.

While by the above referred to measures a corresponding decrease in the formation of blue smoke and irritating substances in the eithaust gases was realized. these steps are not satisfactory because the additional means for practicing these measures bring about an increase in Costs and a decrease in the performance of the engine. especially under full load. Furthermore. any additional means always increase the possibility of disrders it has furthermore been suggested by simple means in estend the fuel injection period in the lower speed range in order to prevent a more pronounced fuel jet tormtition. This suggestion brings about an improvement but still fails to lead to the hoped for result.

It is. therefore. an object of the present invention. Hllt internal combustion engines of the above roentioned type. to find a new way and means by which it will be possible in a simple and uncomplicated way and \slIhtlUI increasing the costs of the engine and without reducing the performance of the engine to obtain a niasimum reduction in the formation of blue smoke.

This object and other objects and advantages of the intention will appear more clearly from the following pecification in connection with the accompanying drawing. in which:

FIG. I illustrates a longitudinal section through the upper portion of ti piston in a cylinder and also shows a fuel jet in the arrangement according to the present invention.

FIG 2 is a top stew of the piston shown in FIG. I and. more specifically. along the line I of HG. I.

llfift FIG 3 represcntsa section taken along the line ll ll of the cylinder-piston arrangement of HG l.

The problem underlying the present IIH'CllIlHfl hits been solsed according to the present invention by marktng the ratio of the diameter of the combustion chamber to the diameter of the neck of the iit tt'thtlsltiiti chamber less than or at maximum equal to I IS iihile the point where the fuel et impacts upon the wall of the combustion chamber is by a corresponding selection of the noule angle and the noule location located within the lower quartet of the combustion chamber While it was heretofore considered necessary to make the ratio of the diameter of the combustion chamber to the diameter of the neck of the combustion chamber higher or at least equal to l: to obtain the necessary turbulence in the combustion chamber. it ll has now been found and proven by numerous lcsls that this ratio is by no means binding if at the same time lltc point where the fuel et impacts upon the wall of lltc Combustion chamber is correspondingly changed In contrad'sstinctton to the present irt cntii'tt. this iitipaet point was heretofore located iii the plane of the manmum diameter of the combustion chamber or slightly therebelow.

Referring rio to the drawing in detail. the piston l shown in part only in FIGS. l-J has II.\ piston bottom 2 provided with a htlll tshitpiltl combustion chamber 3 having a diameter l). The combustion chamber com municatcs with the inner chamber of the cylinder 5 through a nwk 4 which is constricted to a diameter d A cutout 6 in the neck 4 serves for in ecting the fuel by means of the invention nozzle 7 which I.\ arranged ill the cylinder head ii at tin incline lhe ratio of the tlldllb eter Dof the combustion chamber to the diameter d ol the neck 4 is termed the opening ratio and is lcss than or at masintuni equal to l.l5.

The equatorial plane of the combustion chamber 3 I indicated b) the dot-dash line 9 while hall' of the low ct portion of the combustion chamber 3 is indicated by .i dot-dash line [0. An arrow ll indicates the direction which is followed by the fuel et in conformity tilt the invention. the jet impacting upon tltc wall I. of the combustion chamber at the point I}. This impact point I] is clearly located in the lower quarter of the coin bustion chamber 3. The dot-dash line [4 indicates the direction of the fuel jet to it was heretofore customary while the point l5 shows the impact point with a heretofore known arrangement of the type hooked. I he change in the direction of the jet is obtained by dc- Creaa'tng the nozzle angle which represents the masimum deviation of the direction of the et front the nor lle ash and can be realircd by a corresponding turning of the injection nonle 7. The noulc angle is. depending on the location of the noule support in the cylinder head. decreased by approsimately from 5 to 7 degrees As will be evident from the abuse. the impro ements according to the present invention bring about a con siderable reduction in the development of blue smoke in the lower road range. whereas in particular in the full load range no decrease in the performance of the engine will occur. Corresponding tests have shown that with the arrangement according to the invention even a reduction in the air twist in the combustion chamber is pouibic whereby an improvement in the delivery rate and a reduction in the gas change buses will be real tlcd Thus. in conformity with a further de clopnicnt t l the invention. it is mutated that the ratio of the circumferentisl speed of the rotating air charge to the axial speed thereof is less than or at a maximum equal to four while the circumferential speed. with regard to the measuring diameter (0.7 cylinder diameter) and the maximum valve strolte. and the axial velocity is equal to the medium piston speed This ratio was here- More customarily selected to be 4.5 0.2.ln other worth. the rotational frequency of the air in the cornhustion chamber is. compared to the heretofore selcctctl optimum values for instance I65 to I75 Hertz lovrered by approximately ltt percent to ISO to l5$ Hertz. These values refer to a medium piston velocity of it) mlsec and a maximum valve stroke.

It is. of course. to be understood that the present intuition is. by no means. limited to the particular showing in the drawing but also comprises any modifications wllltllt the scope of the appended claims.

Thus. tvhile the drawing shows the ball-shaped cornhuflion chamber provided in the piston. it may instead also be provided in the cylinder head without in any way affecting the essence of the present invention.

I claim:

I. An air compressing direct injection internal comhustion engine having a reciprocatory piston forming a first element and having a pertaining cylinder head forming a second element. one of said elements being provided tsith a ball-shaped combustion chamber which has a neck that is constricted with regard to the diameter of said comhustirm chamber and which is adapted to receitc the combustion air as to circulate the same in said combustion chamber. the ratio of the diameter of said combustion chamber to the diameter of said neck not exceeding I. IS. said engine also having a fuel injection nozzle associated with said combustion chamber and so directed toward the inside of said combustion chamber that the fuel jet injected by said fuel injection nonle passes through a plane which is parallel to said neclt and is spaced from the opposite end of said chamber one-fourth of the distance from said end to said neck and to a point of impact upon the inside surface of said combustion chamber between said plane and said end to form a thin film of fuel on the wall of said chamber which is removed in vapor form through circulating combustion air. the ratio of the circumferential velocity of the air charge in said combustion chamber to the axial apeed of said air charge being not in excess of 4. said circumferential velocity aith reference to said measuring diameter (0 cylinder diametcrl and to maximum valve stroke substantially equa|- ling the mean velocity of said piston 

1. An air compressing direct injection internal combustion engine having a reciprocatory piston forming a first element and having a pertaining cylinder head forming a second element, one of said elements being provided with a ball-shaped combustion chamber which has a neck that is constricted with regard to the diameter of said combustion chamber and which is adapted to receive the combustion air as to circulate the same in said combustion chamber, the ratio of the diameter of said combustion chamber to the diameter of said neck not exceeding 1.15, said engine also having a fuel injection nozzle associated with said combustion chamber and so directed toward the inside of said combustion chamber that the fuel jet injected by said fuel injection nozzle passes through a plane which is parallel to said neck and is spaced from the opposite end of said chamber onefourth of the distance from said end to said neck and to a point of impact upon the inside surface of said combustion chamber between said plane and said end to form a thin film of fuel on the wall of said chamber which is removed in vapor form through circulating combustion air, the ratio of the circumferential velocity of the air charge in said combustion chamber to the axial apeed of said air charge being not in excess of 4, said circumferential velocity with reference to said measuring diameter (0.7 cylinder diameter) and to maximum valve stroke substantially equalling the mean velocity of said piston. 